The present invention relates generally to the field of hardware testing and pertains more particularly to a method of and apparatus for discovering the operational range of an electronic device.
Testing of electrical components, such as microprocessors, and other hardware components ensures proper operation of the particular components. In addition, testing of the hardware components helps define the operational specifications, as defined by a plurality of operating parameters, over which the hardware component is operational.
Various operating parameters are varied to test for and discover the electrical operating ranges of the hardware component. A specific set of conditions as defined by the various operating parameters is referred to as a point.
Previously, automatic testing of the hardware device to discover the electrical operating ranges of a hardware component entailed testing of all the points within a predefined testing region. This process is undesirable for various reasons, all of which increase the amount of time needed for testing.
Prior art FIG. 1 is a plot diagram 100 illustrating tested points within a predefined testing region. In the diagram 100, two operating parameters are varied. Points designated by the letter xe2x80x9cFxe2x80x9d indicate a failure by the hardware component. Points designated by a xe2x80x9cdotxe2x80x9d indicate an successful operation by the hardware component. The testing region is defined by a first operating parameter on the horizontal axis, and a second operating parameter on the vertical axis, and includes all the points in diagram 100. The first operating parameter varies with values ranging from 3.3 to 3.465. The second operating parameter varies with values ranging from 1.71 to 1.80. These parameters can include input/output voltages, clock frequencies, and temperature, etc.
In the past, testing of all the points in a predefined testing region often times would not provide any additional useful information. For example, once an operational boundary is found, further points within the operational boundary need not be tested, and further points outside the operational boundary need not be tested. Although further testing of points inside or outside of the operational boundary was unnecessary, these points were still tested.
For example, looking at diagram 100, the point with parameter coordinates of 1.8 and 3.3 is clearly within the operational range of the hardware component and need not be tested. Similarly, the point with parameter coordinates of 1.71 and 3.465 is clearly outside of the operational range of the hardware component and also need not be tested. No further information is gained from testing these two points.
Testing of points within a testing region adds and wastes a significant amount of time for each point tested unnecessarily. Referring back to Prior Art FIG. 1, once the operational boundary is fully determined within the testing region, no other points need be tested. For example, once adjacent failure points that are also adjacent to operational points are discovered within the region, testing of the remaining points provides limited or no further information. Points within region 110 define the operational boundary for the hardware component tested in diagram 100. For example, failure points outside of region 110 are unnecessarily tested.
Furthermore, the predefined testing region provides a limitation to the discovery of the operational specifications of the hardware component. The testing region is defined manually as a best guess estimate. Should the testing region be too small, the region may not include all of the operational boundary for the hardware device. In that case, the testing region needs further manual expansion and retesting of the expanded region. On the other hand, if the testing region is too large, the region will include too many unnecessary points for testing, thereby wasting testing time, energy, and resources.
Embodiments of the present invention describe a method and apparatus for conducting a boundary search for shmoo tests on an electronic device. Specifically, a method of testing operational boundaries is described in one embodiment of the present invention. The method discloses the discovery of an operational range for a hardware device over a plurality of varying operating parameters. The operational range is discovered by testing points, as defined by the plurality of varying operating parameters, to discover an operational boundary of the device. The operational boundary comprises a plurality of boundary points that lie just outside of the operational range of the device. The operational boundary is discovered automatically and without testing all of a plurality of interior operational points within the operational boundary.